I haven't seen a guild has factory/offices somewhere other than Naldiq & Vymelli's (BSM/ARM, in Moraby Drydocks).
The guilds afaik are separate from mass producing, mostly for learning the art and new ways to fit clients needs.
ALC guildmaster is too quirky to run a factory. LTW's naturalist and not wasting parts from animals guild motto.
I think paper is more common than parchment in Eorzea, Ishgard may have more because winter preserve some animals.